Erotic sexual denial is when two people have fun by teasing each other sexually without ever letting either person fully orgasm. It's like playing a game where the goal is to delay the "finish line" as long as possible. It's like when you have a really good piece of candy and you're trying to make it last as long as possible by sucking on it slowly.
One person who is in charge of the game, usually called the "dominant," will tell the other person, called the "submissive," when they can orgasm or not. Sometimes, they might even make them stop right when they're about to have an orgasm, which can be really frustrating, but also really exciting at the same time.
It's important to remember that this game requires a lot of trust and communication between the two people playing. They have to make sure they both feel comfortable with the rules of the game and that nobody is ever made to do something they don't want to do.
Overall, erotic sexual denial is a type of game that some people like to play to make their sexual experiences more exciting and fun.